While it's true that as we gain more experiences, we can better emphasize with the pain and joy of others. However, we also gain experiences that can harden our emotions. Some people may become more emotional as a result of their life experiences while others will become more hardened.
I'll use myself as an example. As a child, there was a period of years where my mother raised me alone. While all people are different, we live in a society where women are more prone to feel comfortable showing emotion. As a result, both my natural emotions and my upbringing made me an extremely sensitive child. Unfortunately, children are cruel and if you respond to bullying, taunting, or other harassment, you become a popular target for it in the future. As a result, I slowly become more emotionally hardened over time. If people think it doesn't bother you, they leave you alone. This was actually an anti-bullying strategy popular when I was growing up, but the fact is that it requires someone to suppress a perfectly natural reaction (crying in response to mistreatment). That's troubling
Along with other adventures through my life, I eventually fell victim to clinical depression. There were times when little things would make me cry easily. I'd be upset because of minor problems or even imagine them. Once, I cried over 94.6% on a test in Middle School. I was getting self-worth from grades and had somehow decided anything below 95% was unacceptable. Regardless, I am a different person when my depression is winning. So I will definitely agree that we change over time when it comes to what makes us cry. It's not always medical, like in my case. I'm sure other things have contributed to my changing reactions.
Unfortunately, I still have a tendency to avoid crying. I think it's a male thing, in many cases. Funerals are usually guaranteed to make me cry unless I bury my emotions, which I typically do. Of course, my tendency to not deal with these emotions results in me occasionally crying over something absolutely ridiculous. The body just isn't meant to ignore its emotions. I'm fortunate that my body does it for me. Others end up with serious medical problems as a result of this kind of behavior.
Now that I think of it, I don't read sad books so I'm not sure if they'd make me cry. Occasionally, movies can compel me to cry. However, I think entertainment tries to avoid making people sad as it costs them money. I also have allergies that can make me cry regardless of whether I want to do so or not. There is also the infamous soap in the eye that mocks you with its "no tears" label while simultaneously melting your eyes. I suspect there are plenty of things that make me cry, but it's not something I really think about often. The last thing is the worst culprit for making me cry. The state of affairs in the world. The fact that people, including myself, often behave in terrible ways really distresses me. Sometimes watching the news makes me think the world was written by a tragedian.